Source of entangled photon pairs generated by low-power pump laser

With the continuous development of optical quantum sensor technology, the importance of quantum entanglement sources is growing. As an essential component of optical quantum systems, entanglement sources have broad applications in quantum communication, imaging, computing, and other fields. However, the high-power consumption and preparation costs associated with these sources hinder their integration and expansion. To address these issues, we conducted experiments using a 40mW laser diode and a typical type-II barium metaborate (BBO) crystal to prepare a low-power and low-cost quantum entanglement source. Our results show an average count of over 15,000 entangled photons per second and over 7,500 entangled photon pairs per second, which are in good agreement with theoretical analysis. We have made significant progress towards achieving the goal of low-power and low-cost entanglement sources, which will facilitate the practical application of quantum entanglement lighting and promote the wider adoption of optical quantum systems in the future.